Concentration of nonmetallic minerals



Patented Jan. 18, 1938 UNITED STATES PATENT- OFFICE CONCENTRATION OFNONMETALLIC MIN- ERALS No Drawing. Application October 18, 1935, SerialNo. 45,599

14 Claims.

The present invention relates to a concentration of so-callednon-metallic minerals from ores containing them in association withsilicious mat ter, the term non-metallic being used herein to refer tothose minerals which are not used in the metallurgical industry as asource of metal contained therein, but which are used for some otherpurpose. Among these minerals are included phosphates, calcite, barite,and fluorspar, the invention being herein described in connection withthe examples given as applied to all four of these minerals.

The general object of the invention is to provide an improved processfor concentrating minerals of the character stated from ores in whichthe gangue is at least in part silicious.

In accordance with the invention, a pulp of suitably divided particlesof the non-metallic mineral ore to undergo treatment is agitated in thepresence of a substantially insoluble and unsaponifiable oil, a lowerfatty acid or lower fatty acid soap to cooperate with said oil ineffecting collection of the non-metallic mineral values, and anactivating agent causing said fatty acid or fatty acid soap to have apreferential aflinity for said values, said activatingagent consistingof a soluble salt of a metal whose oxide does not exert an alkalinereaction when added to water. Thereafter, a concentrate is separatedfrom the pulp by froth flotation or in other manner known in the art. Bysuch procedures it has been found that excellent results may beobtainedwith relation to both recovery of the non-metallic mineralvalues and content of said values in the concentrate. The lower fattyacid or lower fatty acid soap employed as a cooperating collector may beany one of the fatty acids or fatty acid soaps having a carbon contentof less than thirteen atoms, satisfactory results having thus beenobtained with caprylic acid, heptylic acid, capric acid, caproic acid,pelargonie acid, and lauric acid, as well as with the soaps of theseacids. In certain cases the addition of an alkali, such as caustic soda,has been found to improve the concentration or to reduce the quantity ofactivating metallic salt necessary.

It is already known that phosphate minerals may be successfullyconcentrated with the aid of fatty acids in conjunction with fuel oiland alkali, or with the aid of fatty acid soaps in conjunction with fueloil, but it has hitherto been supposed that the only fatty acids orfatty acid soaps capable of successful use were those containing morethan twelve carbon atoms. The successful use of the lower fatty acids orlower fatty acid soaps according to the present inven-, tion is duefundamentally to the employment of soluble metallic salts therewith. Thepresence of the metallic salt, with or without addition of alkali, maynot only have the effect of considerably improving the results ofconcentration, but may also have the effect of considerably decreasingthe quantity of the lower fatty acid or lower fatty acid soap required.The metallic salt may even enable concentration to be effected wherenone whatever can be practicably obtained without it, regardless of theamount of fatty acid 15 or fatty acid soap employed.

In most forms of the invention herein described in connection with theexamples given, the pulp containing the ore of the mineral to beconcentrated is of an acid character subsequent to mixing with thereagents employed; that is, the pH of the pulp is less than the indexnumber 7, corresponding to a neutral condition. This acid character ofthe pulp is obtained with the lower fatty acids employed in a free stateor added to the pulp uncombined with other substances, and is due to thesolubility of such acids in water, it being observed that solubility ofthe fatty acids of carbon content of less than thirteen atoms is muchgreater as compared with the -fatty acids of carbon content of more thantwelve atoms. It should also be noted that the acid character of thepulp is in general not nullified by the use of alkali in conjunctionwith the metallic salt; that is, the pH of the pulp is still below 7even after the addition of alkali in the quantity determined to besuitable for maximum concentration. j

In preparing the ore for treatment by the process of the presentinvention, it is in general desirable that it be comminuted to aparticle size most suitable for eflicient operation and that it belargely deslimed, its desliming greatly minimizing the consumption ofthe reagents. Ordinarily, the crude ore is first subjected to apreliminary grinding operation and thereafter screened or classified toremove all particles other than those desired. The undersize may then bedeslimed, and the oversize reground, deslimed, and added to the deslimedundersize; or the oversize may be reground, added to the undeslimedundersize, and the whole then deslimed.

Although the procedures described in the fol lowing examples areflotation procedures, it is known that satisfactory results may in many7 and Littleford No. 1,968,008, of July 24, 1934.

Example 1 Deslimed phosphate feed to the flotation concentration plantof the Phosphate Recovery Corporation in Mulberry, Florida, consistingmainly of calcium phosphate and silica and of a particle size to passthrough a screen of 28 meshes to the lineal inch, was made up with waterto a thick pulp of 70% solids.

To this pulp were added during agitation in an impeller-type mixer, 2pounds of lead nitrate, 6 pounds of fuel oil, 36.9 pounds of caproicacid, and 0.14 pound of a frothing agent consisting of 3 parts of cruderosin residue dissolved in 1 part of kerosene oil, the reagent amountsstated all referring to proportions figured on the basis of the dryweight tonnage (2,000 pounds) of material treated. This addition ofreagents required about one minute, subsequent to which agitation wascontinued for two more minutes. After this mixing the pulp wastransferred to a laboratory subaeration flotation machine, where it wasdiluted and agitated for a period of less than two minutes, during whicha rougher concentrate was separated. Upon removal of the tailing, therougher concentrate was refioated without further addition of reagents,a final concentrate being thus obtained. The tailing of this cleaningwas assayed separately and was found to constitute a middling, which incommercial operation would be returned to the flotation cells forfurther extraction of values. The results of the test are indicated inthe following table:

19 4): percent assay Insol- Ratio of uble percent Weight Comparativetest 1 A sample of the same feed was similarly formed into a thick pulpwith water, and to this pulp were added 2 pounds of caustic soda, 2pounds of fuel oil, pounds of caproic acid, and 0.14 pound of HerculesPowder Companys Tarol #2 (a mixture of three parts of steam distilledpine oil and 1 part of rosin oil), all per ton of dry material. Soonafter agitation of the pulp with these reagents was started, it wasapparent that their nature was not such that successful flotation couldbe efiected. The period of agitation was thus lengthened to as much asten minutes, and during this extended agitation further additions ofcaustic soda at the rate of 2 pounds per ton and further additions ofcaproic acid at the rate of 10 pounds per ton were repeatedly made,until a total of 40 pounds of caustic soda and a total of 100 pounds ofcaproic acid were present in the pulp. Upon dilution and agitation 'inthe flotation machine, no flotation whatever could be effected with thematerial thus treated.

In the above comparative test it is to be noted that only 2 pounds offuel oil were used as compared to 6 pounds in Examples 1 and 2. This, isdue to the fact that in the comparative test no reaction could beobtained between the reagents and the pulp with which they were admixed.The pulp did not take up even as much as 2 pounds of fuel oil, so it wasconsidered useless to increase the amount.

Example 3 A pulp of the same feed and of the same consistency as beforewas agitated with 1.50 pounds of lead nitrate, 6 pounds of fuel oil,14.74 pounds of heptylic acid, and 0.14 pound of the same item--sene-rosin solution as described in Example 1, all per ton of drymaterial. The procedures were otherwise the same as in Example 1, thefollowing results being obtained:

IFQQQ seas pH of pulp after mixing with reagents 3.8.

Example 2 The same feed was taken and the same procedures were followedas in Example-1; but in this instance caustic soda in the amount of 1-pound per ton was also employed and the proportion of lead nitrate wasreduced to 1 pound per ton, the proportions of fuel oil, caproic acid,and kerosene-rosin solution remaining the same The lead nitrate andcaustic soda were mixedgtpgether prior to addition to the pulp, the.caustic 'soda employed being a commercial brand of hydroxide.Notwithstanding the reducedouantity of lead nitrate, a concentrate ofsubstantially the same grade as before was obtained, as shown by thefollowing table:

Insolpercent 16 4): percent recovery :(P 4): percent assay Ratio ofconcentratlon Weight Product percent a es pH of pulp after mixing withreagents 4.4.

As a basis of comparison with the examples which have been described,the following test was carried out.

we! ht Ca;(P04): Insol- 051(104): Ratio 0! Product 3 percent ublepercent concenpercent assay percent recovery tretion Feed 100.0 28.53100.0

Concentrate..- 34. 2 73. 6. 61 87. 7 2. 92

Middling- 5. 4 19. 69 3. 7

Taillng 60. 4 4. 06 8. 6

pH of pulp after mixing withreagents less than 6.

Example 4 The procedures of Example 3 were repeated on another sample ofthe same phosphate feed, but instead of the 1.50 pounds per ton of leadnitrate a mixture of 1 pound per ton of lead nitrate and 1 pound per tonof caustic soda was added to the pulp. The same proportions of the otherreagents were employed, the results being as follows: 1

Ca (P04); Insol- Co; (PO )1 Ratio of Product 332%: percent uhle percent:concenessay Feed 100.0 23.00 Concentrate--- 32. 0 77. 17 Middling.-- 9.51 31.05 Telling as 1.79

pH of pulp after mixing with reagents less than 6.0.

\ comparative test 2 A sample of the same feed as before was treatedwith 36 pounds (total) per ton of caustic soda, 2 pounds per ton of fueloil, 100 pounds (total) Example 5 In the same manner as indicated inExample 1, flotation was effected on a pulp of the same feed as beforebut employing as reagents and proportions thereof: 1 pound per ton oflead nitrate, 6 pounds per ton of fuel oil, 6.07 pounds of caprylicacid, and 0.14 pound of the kerosenerosln solution, the followingresults being obtained:

Wei m Ca; (P04): Insol- Ca; (P04): Ratio oi Product etcgnt percent ublepercent concenp assay percent recovery tration Feed 100.0 28. 39 100.0Concentrate... 25. 7 77. 77 7. 34 70. 4 I). 89 iddling- 22. 5 28. 8422.9 Tailing 51. 8 3. 68 6. 7

pH of pulp after mixing with reagents less than 6.0.

Example 6 7 With the same reagents as in Example 5, but with theproportions of lead nitrate and caprylic acid respectively reduced to0.65 pound per ton and 6. pounds per ton, and with the lead nitrateadded in admixture with 1v pound per ton of caustic soda, the followingresults were obtained, the same feed as before being employed:-

ht C83 (P04): lnsol- Ca: (P Ratio of Product g percent uble percentconcenper assay percent recovery tration pH of pulp after mixing withreagents less than 6.0.

Example 7 For the purpose of this example caprylic acid was used inconjunction with copper sulphate admixed with caustic soda, fuel oilbeing also employed together with the same kerosene-rosin solution aspreviously described. Flotation was effected on a pulp of the same feedas before, the reagents being present in the pulp in the followingproportions: copper sulphate 1 pound, caustic soda 1 pound, fuel oil 6pounds, caprylic acid 6 pounds, and kerosene-rosin solution 0.14

pound, all per ton of dry material. The results were as follows:-

m CH: (P04): Insol- Ca: (P0 Ratio of Product Denim percent uble percentconcen assay percent recovery tration Feed 100. 0 28. 11 100.0Concentrate... 22. 2 77. 47 7. 26 61. 2 4. 49 Middling. 28. 0 24. 62 24.Tailing.-- 49.8 8. 08 l4. 3

pH of pulp after mixing with reagents less than 6.0.

Example 8 The same procedures as outlined in detail in Example 1 wereagain carried out on a sample of the same phosphate feed, but employingthe following reagents and proportions thereof: zinc sulphate 1 pound,caustic soda 1 pound, fuel oil 6 pounds, caprylic acid 6 pounds, andkerosene-rosin solution 0.14 pound, all per ton of dry mineral, the zincsulphate and caustic soda being added as a mixture to the pulp. Theresults were as follows:

Wei ht Ca; (P091 Insol- Ca; (P04); Ratio oi Product eregnt percent ublepercent concenp assay percent recovery tration Feed 100. 0 28. 03 100.0Concentrate... 21. 3 79. 68 4. 60 60. 5 4. 70 Middling. 11.9 56. 77 24.l Tailing 66. 8 6. 43 15.4

pH of pulp after mixing with reagents than 6.0.

Example 9 The same phosphate feed was employed, with aluminum chlorideas the activating salt. The reagents were used in the followingproportions: aluminum chloride 1 pound, caustic soda 0.8 pound, fuel oil6 pounds, caprylic acid 6 pounds, and kerosene-rosin solution 0.14pound, all per ton of dry material, the aluminum chloride and causticsoda being added as a mixture to the pulp. The results were as follows:-

- C83 (P04): Insol- Ca; (P04): Ratio of Product gags: percent ublepercent concenp v assay percent recovery tration 28. 68 100. 0 71. 9412. 93 82. b 12. 4-1 l0. 2 4. 68 7. Z

pH of pulp after mixing with reagents less than 6.0.

Example Ferrous chloride was the salt, the feed being the same asbefore. The reagents were employed in the following proportions: ferrouschloride 1 pound, caustic soda 1 pound, fuel oil 6 pounds, caprylic acid6 pounds, and kerosene-rosin solution 0.14 pound, all per ton of drymaterial, the ferrous chloride and caustic soda being added as a mixtureto the pulp. The results were as follows:

- Weight 053(104): Insol- Cm(P04) Ratio of Product percent percent ublepercent concen assay percent recovery tration Feed 100. 0 28. 08 100. 0

Concentrate.-. 21. 4 79. 47 4. 93 60. 5 4. 67

iddling..... 14.0 57. 39 28. 7

Tailing 64. 6 4. 76 l0. 8

pH of pulp after mixing with reagents less than 6.0.

Comparative test 3 A sample of the same feed as before was processed inthe manner indicated in comparative test 1, but employing the followingreagents and proportions thereof: caustic soda 24 pounds (total), fueloil 2 pounds, caprylic acid 70 pounds (total), and the samekerosene-rosin solution as previously described 014 pound. all per tonof dry material. These reagents were also found to be otallyineflective, thereasons for employing only 2 pounds of fuel oil beingagain the same as expressed in connection with comparative test 1.

By the use of fuel oil and caprylic acid as the only reagents in anothertest, a recovery of 82.1% was effected in a concentrate assaying 73.21%calcium phosphate, but this flotation required the use of pounds per tonof such acid.

Example 11 As shown by the following table, a sample of the same feed asbefore was successfully concentrated by the procedures indicated indetail in Example 1, but employing the following reagents andproportions thereof: lead nitrate 1 pound, fuel oil 4 pounds, pelargonicacid 4.09 pounds, and

the same kerosene-rosin solution 0.14 pound, all per ton of drymaterial:-

Ca;(P04)a Insol- CadPOr): Ratio of Product ggg: percent uble percentconcenpe assay percent recovery tration Feed 100.0 28.80 100.0

Concentrate..- 32. 0 73. 14 5. 04 s1. 3 a. 12

Middliug...-. 7.1 32.:11 a7 Tailing 60.3 4.86 10.0

pH of pulp after mixing with reagents 5.5.

Example 12 Successful concentration was also effected on another sampleof the same phosphate feed by the use of the same reagents andproportions indicated in Example 11, but with the 1 pound per ton oflead nitrate replaced by a mixture of 0.5 pound per ton of lead nitrateand 0.75 pound per Comparative test 4 A sample of the same feed asbefore was processed in the manner indicated in comparative test 1, butemploying 20 pounds (total) of caustic soda and 55 pounds (total) ofpelargonic acid,

both per ton of 'dry material. There were no other reagents employed, noconcentration whatever being effected.

In another test the use of pelargonic acid alone yielded a concentrateassaying 72.08% of calcium 7 phosphate and containing 88% of the calciumphosphate originally present in the sample employed, but 55 pounds perton of such acid were necessary to effect the concentration.

Example 13 Again following procedures similar to those indicated inExample 1, another sample of the same phosphate feed was concentratedwith the aid of the following reagents and proportions thereof: amixture of 0.65 pound per ton of lead nitrate and 1 pound per ton ofcaustic soda, 5 pounds per ton of fuel oil, 3 pounds per-ton of capricacid, and 0.14 pound of the kerosene-- rosin solution. The results wereas follows:

pH of pulp after mixing with reagents less an 6.0.

Comparative test 5 A sample of the same feed as before was processedwith the following reagents and proportions thereof: caustic soda 0.4pound, fuel oil 2 pounds, capric acid 6 pounds, and kerosene-rosinsolution 0.14 pound, all perton of dry material. While a concentrateassaying. 72.29% in calcium phosphate and containing 70.5% of thecalcium phosphate present before concentration was obtained, yet theseresults were obtained with a quantity of capric acid twice that employedto obtain superior results in Example 13. Here again it was considereduseless to increase the amount of fuel oil over 2 pounds, as the pulptreated with the reagents indicated did not even take up this amount.

Example 14 as previously described, all per ton of dry material, thelead nitrate and the caustic soda being added as a mixture to the pulp.The procedures were otherwise the same as outlined in detail in Example1, the following results being obtained:

. Ca; (P04); lnsol- Cm (P04): Ratioof Product 3353: percent uble percentconcenasssy percent recovery (ration Feed 100.0 41.09 Concentrate.-- 45.2 79. 17 3. 67 Mlddling. 3. 9 51. 97 Tailing 50.9 6.44

pH of pulp after mixing with reagents 8.6.

Comparative test 6 A sample of the same feed 'as in Example 14 wasprocessed in the same manner as in that example, except that the use oflead nitrate was omitted, the same proportions of caustic soda, fueloil, lauric acid, and kerosene-rosin solution being employed. Whereas aconcentrate assaying 79.67% in calcium phosphate was obtained,

the amount of calcium phosphate recovered in said concentrate was only72.6% as compared to the 87.1% recovered in Example 14.

Example 15 A synthetic mixture of marble and silica sand was prepared inthe proportion of about 20% marble and sand. This mixture was sized on ascreen having 28 meshes to the lineal inch, and the undersize materialwas formed with water into a pulp of 10% solids. To this pulp. wereadded, during agitation in the mixer, 1 pound per ton of lead nitrate, 4pounds per ton of fuel oil, 3.67 pounds per ton of caprylic acid, and0.14 pound per ton of the kerosene-rosin solution previouslydescribed,the total period of agitation being three minutes. After this mixingoperation, the pulp was diluted and agitated in the flotation machinefor approximately one minute. during which a rougher concentrate wasseparated. The tailing was removed, whereupon the rougher concentratewas reiioated without further addition of reagents, yielding a finalconcentrate. The tailing of this cleaning was assayed separately and wasfound to constitute a middling, which in commercial operation would bereturned to the'fiotation cells for additional recovery of values. Theresults are indicated in the following table:

A similar mixture of marble and silica sand was treated with the aid of1 pound per ton of ferric chloride, 4 pounds per ton of fuel oil, 3.67pounds per ton of caprylic acid, and 0.14 pound per ton of the samekerosene-rosin solution, the procedures followed being otherwiseidentical to those outlined in Example 15. The following results wereobtained:

Wei ht CaCO; CaCO; Ratio of Product g percent percent concenpe assayrecovery tration Feed 100. 0 20. 90 100. 0 Concentrate 20. 4 95. 43 03.0 4. 89 Middling 2. 8 45. 58 6. 1 Telling 76. 8 0. 10 0. 9

pH of pulp after mixing with reagents 6.0.

Example 17 Again repeating the procedures of Example 15, but treatingthe marble containing pulp with 0.5 pound per ton of copper sulphate, 4pounds of fuel oil, 2.76 pounds of caprylic acid, and 0.14 pound of thekerosene-rosin solution, the following results were obtained:

weight CaCOa (M703 Ratio of Product percent percent percent comen assayrecovery trait mu pH of pulp after mixing with reagents Comparative test7 A similar mixture of marble and sand was processed in the same mannerand with the same reagents and proportions as in Example 15, except thatlead nitrate was not employed. The following results were obtained, itbeing observed that while a concentrate assaying 95.43% in calciumcarbonate was obtained, only 59.3%

5 of the-calcium carbonate originally employed was recovered.

A crude high-grade barite matrix from Cartersville, Georgia, was takenfor the purpose of this example. A sample of this ore was ground andsized on a screen of 35 meshes to the lineal inch, and the oversizematerial reground to pass through the same screen, the total samplebeing then deslimed and made up into a thick pulp with water. This pulpwas agitated in the mixer with 1 pound 'per ton of lead nitrate, 2.50pounds per ton of fuel oil, 1.84 pounds per ton of caprylic acid, and0.14 pound of the kerosene-rosin solution previously described. The pulpwas then diluted and agitated in the flotation machine, a rougherconcentrate being separated which, upon removal of the tailing, wasagain floated without further addition of reagents, yielding a finalconcentrate. The tailing of this cleaning is indicated as a middling inthe following tablez- B880 B: C02 B88 04 RMlO 01 Product Weight percentperperpercent concenassay cent cent recovery tration Feed 100. 0 92. 375. 46 100.0 Concentrate.- 5. 2 95. 90 0. 94 0. 30 5. 4 19. 23

iddllng 62.5 95. 48 2.56 64.6 Taillng 32.3 85.76 11.79 30.0

Example 19 The identical procedures of Example 18 were repeated onanother sample of the same ore, but with the proportion of caprylic acidincreased to 5.52 pounds per ton. The following results were obtained:

Weight BaSO4 S10: 00 B8804 Ratio oi Product mom percent perperpercentconcenp v assay cent cent recovery tration Feed 100. 0 92. 22 5. 73100.0 Conccntrate 75.2 95.04 3.12 0.25 77.4 Middling 23.2 87.97 0.6222.1 Tailing l. 6 24. i4 69. 72 0. 5

Comparative test 8 With the proportion of caprylic acid the same as inExample 19, still another sample of the same ore was processed in thesame manner as in Example 181 but with no addition of lead nitrate. Thefollowing results were obtained, the particularly low recovery beingobserved:

Comparing the latter table with that of Example 18, it will be notedthat one-third as much caprylic acid when used with lead nitrate gives16% more barium sulphate recovery in a rougher concentrat ofsubstantially the same grade than when lead nitrate is omitted. Y

Example a A synthetic mixture of approximately equal quantities offiuorspar and quartz, and of a particle size to pass through a screen of28, meshes to the lineal inch, was made up with water to a pulp of70%solids. This thick pulp was agitated in the mixer with 1 pound oflead nitrate, 2.46 pounds of fuel oil, 2.46 pounds of caprylic acid, and0.14 pound of the same kerosene-rosin solution as already described.After this mixing operation, the pulp was diluted and agitated in theflotation machine, yielding a rougher concentrate. The tailing wasremoved, whereupon the rougher concentrate was refioated without furtheraddition of reagents, yielding a final concentrate.

The tailing of this cleaning is indicated as a mid- Comparative test 9The identical procedures of Example 20 were repeated on a similarmixture of fiuorspar and quartz, except that the use of lead nitrate wasomitted, the same proportions of fuel oil, caprylic acid, andkerosene-rosin solution being employed. A'concentrate and a middlingwere obtained each assaying about the same calcium fluoride content asin Example 20, but the total calcium fluoride recovery effected in.bothconcentrate and mid-' dling was only 63.7% as compared to the 83.2% inExample 20.

Experiments carried out with the view to determine the effect of theorder of addition of the reagents on grade of concentrate and recoveryof values have shown that there is no general method of addition by whch best results may be obtained in all cases. In this respect onemetallic salt may behave differently from another, and in certain casesthere may be several methods of addition that will insure mostsuccessful concentration. Thus, when concentrating a phosphate mineraland employing fuel oil, caprylic acid, lead nitrate, and caustic soda asreagents, three'different procedures have been determined by the use ofeither one of which equal and highest results are obtainable. Accordingto one of these alternatives, lead nitrate is first added to the pulp,and thereafter are added, in the order in which they appear, causticsoda, fuel oil,-and caprylic acid. Another of these alternativesconsists in first adding fuel oil to the pulp and thereafter, in theorder in which they appear, caprylic acid, lead nitrate, and

caustic soda. The third alternative consists in first adding leadnitrate and caustic soda. as a mixture to the pulp and thereafter, inthe order in which they appear, fuel oil, and caprylic acid. Employingcopper sulphate instead of lead nitrate, only one method of addition hasbeen found to be then capable of giving highest results, and it does notconform to any of the three when lead nitrate is employed, this methodconsisting in first adding fuel oil to the pulp and thereafter, in theorder in which they appear, caprylic acid, caustic soda,

and copper sulphate. Employing aluminum chloride as the metallic salt,again only one method of addition has been found to be capable of givinghighest results, but in this instance it conform to the first-mentionedof the three procedures possible when lead nitrate is employed,therefore consisting in first adding aluminum chloride to the pulp andthereafter, in the order in which they appear, caustic soda, fuel oil,and caprylic acid.

It is thus apparent that the invention is not broadly limited to anyspecific method of addition of the reagents to the pulp, the method tobe adopted which will insure most successful concentration in eachindividual case being of course capable of determination by simpleexperimentation. Moreover, while it is true that in certain caseshighest results are obtained by following certain procedures ofaddition, yet it is not essential that these procedures be followed inorder that satisfactory concentration may be eflected.

It is also desired to have it understood that the invention is notbroadly limited to any specific proportions of the reagents, theproportions suitable'for most successful concentration being 'alsocapable of determination by simple experimentation in practice. None ofthe procedures described in detail herein should be interpreted aslimiting the invention, these procedures being capable of .beingmodified in many ways without departing agent consisting of a solublesalt of a metal whose oxide does not exert an alkaline reaction whenadded to water, and separating a concentrate relatively rich in saidvalues and relatively poor in silicious matter.

2. The process of concentrating non-metallic minerals from ores.containing them in association with silicious matter, which comprisesagitating a pulp of suitably divided particles of such a non-metallicmineral ore in the presence of a substantially insoluble andunsaponifiable oil, a

of the non-metallic mineral values, and an activating agent causing saidfatty acid soap to have a preferential afiinity for said values, saidactivating agent consisting of a soluble salt of a metal whose oxidedoes not exert an alkaline reaction when added to water, and separatinga concentrate relatively rich in said values and relatively poor insilicious matter. I

3. The process of concentrating non-metallic minerals from orescontaining them in association with silicious matter, which comprisesagitating a pulp of suitably divided particles of such a non-metallicmineral ore in the presence of a substantially insoluble andunsaponifiable oil,v a fatty acidof less than thirteen carbon atoms tocooperate with said oil in effecting collection of the non-metallicmineralvalues, and an activating agent causing said fatty acid to have apreferential affinity for said values, said activating agent consistingof a soluble salt of a metal whose oxide does not exert an alkalinereaction when addedto water, and subjecting the pulp to froth flotationso as to separate a float relatively rich in said values and relativelypoor in silicious matter.

4. The process of concentrating non-metallic minerals from orescontaining them in association with silicious matter, which comprisesagitating a pulp of suitably divided particles of such a non-metallicmineral ore in the presence of a substantially insoluble andunsaponifiable oil, a fatty acid soap of less than thirteen carbon atomsto cooperate with said 011 in effecting collection of the non-metallicmineral values, and an activating agent causing said fatty acid soap tohave a preferential aflinity for said values, said activating agentconsisting of a soluble salt of a metal whose oxide does not exert analkaline reaction when added to water, and subjecting the pulp to frothflotation so as to separate a float relatively rich in said values andrelatively poor in silicious matter.

5. The process of concentrating non-metallic minerals from orescontaining them in association with silicious matter, which comprisesagitating a pulp of suitably divided particles of such a non-metallicmineral ore in the presence of a substantially insoluble andunsaponifiable oil, a fatty acid of less than thirteen carbon atoms tocooperate with said oil in effecting collection of the non-metallicmineral values, an activating agent causing said fatty acid to have apreferential affinity for said values, and an alkali, said activatingagent consisting of a soluble salt of a metal whose oxide does not exertan alkaline reaction when added to water, and separating a concentraterelatively rich in said values and relatively poor in silicious matter.

6. The process of concentrating non-metallic minerals from orescontaining them in association with silicious matter, which comprisesagitating a pulp of suitably divided particles of such a non-metallicmineral ore in the presence of a substantially insoluble andunsaponifiable oil, a fatty acid soap of less than thirteen carbon atomsto cooperate with said oil in effecting collection of the non-metallicmineral values, an activating agent causing said fatty acid soap to havea preferential affinity for said values, and an alkali, said activatingagent consisting of a soluble salt of a metal whose oxide does not exertan alkaline reaction when added to water, and separating a concentraterelatively rich in said values and relatively poor in silicious matter.

'I. The process of concentrating non-metallic minerals from orescontaining them in association with silicious matter, which comprisesagitating a pulp of suitably divided particles of such a non-metallicmineral ore in the presence of a substantially insoluble andunsaponifiable oil, caprylic acid to cooperate with said oil ineffecting collection of the non-metallic mineral values, and anactivating agent causing the caprylic acid to have a preferentialaffinity for said values, said activating agent consisting of leadnitrate, and separating a concentrate relatively rich in said values andrelatively poor in silicious matter,

8. The process of concentrating non-metallic minerals from orescontaining them in association with silicious matter, which comprisesagitating a pulp of suitably divided particles of such a non-metallicmineral ore in the presence of a substantially insoluble andunsaponifiable oil, caprylic acid to cooperate with said oil ineffecting collection of the non-metallic mineral values,

an activating agent causing the caprylic'acid to have a preferentialafllnity for said values; and caustic soda, said activating agentconsisting of lead nitrate, and separating a concentrate relatively richin said values and relatively poor in silicious matter;

9. The process of concentrating phosphate minerals from ores containingthem in association with silicious matter, which comprises agitating apulp of suitably divided particles of such a phosphate ore in thepresence of a substantially insoluble and unsaponiflable oil, a fattyacid of less than thirteen carbon atoms to cooperate with said oil ineffecting collection of the phosphate values, and an activating agentcausing said fatty acid to have a preferential aflinity for said values,said activating agent consisting of a soluble salt of a metal whoseoxide does not exert an alkaline reaction when added to water, andseparating a concentrate relatively rich in said values and relativelypoor in silicious matter.

10. The process of concentrating phosphate minerals from ores containingthem in association with silicious matter, which comprises agitating apulp of suitably divided particles of such a phosphate ore in thepresence of a substantially insoluble and unsaponifiable oil, a fattyacid soap of less than thirteen carbon atoms to cooperate with said oilin effecting collection of the phosphate values, and an activating agentcausing said fatty acid soap to have a preferential affinity for saidvalues, said activating agent consisting of a soluble salt of a metalwhose oxide does not exert an alkaline reaction when added to Water, andseparating a concentrate relatively rich in said values and relativelypoor in silicious matter.

11. The process of concentrating calcite from ores containing it inassociation with silicious matter, which comprises agitating a. pulp ofsuitably divided particles of such a calcite ore in the presence of asubstantially insoluble and unsaponifiable oil, a fatty acid of lessthan thirteen carbon atoms to cooperate with said oil in effectingcollection of the calcite values, and an activating agent causing saidfatty acid to have a preferential'afilnity for said values, saidactivat: ing agent consisting of a soluble salt of a metal whose oxidedoes not exert an alkaline reaction when added to water, and separatinga concentrate relatively rich in said values and relatively poor insilicious matter.

12. The process of concentrating calcite from ores containing it inassociation with silicious matter, which comprises agitating a pulp ofsuitably divided particles of such a calcite ore in the presence of asubstantially insoluble and unsaponifiable oil, a fatty acid soap ofless than thirteen carbon atoms to cooperate with said oil in effectingcollection of the calcite values, and an activating agent causing saidfatty acid soap to have a preferential affinity for said values, saidactivating agent consisting of a soluble salt of a metal whose oxidedoes not exert an alkaline reaction when added to water, and separatinga concentrate relatively rich in said values and relatively poor insilicious matter.

13. The process of concentrating barite from ores containing it inassociation with silicious matter, which comprises agitating a pulp ofsuitably divided particles of such a barite ore in the presence of asubstantially insoluble and unsaponiflable oil, a fatty acid of lessthan thirteen carbon atoms to cooperate with said oil in effectthepresence of a substantially insoluble and unsaponifiable oil, a fattyacid soap of less than thirteen carbon atoms to cooperate with said oilin effecting collection of the barite valuu. and an activating agentcausing said fatty acid soap to have a preferential amnity for saidvalues, said activating agent consisting of a soluble salt of a metalwhose oxide does not exert an alkaline reaction when added to water, and

separating a concentrate relatively rich in said 10 values and relativey poor in silicious matter.

FRANCIS x. TAR'I'ARON.

